Locomotive arch



Ams, 1923.

C. E. MILLER 450696 LOCOMOTIVE ARCH Fle d Mar. 5, 1920 U E T ies oFFic.

CIEARLES E. MILLER, OF CHICAGO, ILLINOIS, ASSIGNOR TOUNIVERSAL ARCH COMIANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS. i

LOCOMOTIVE ARCH.

Application mea March 5,1920. serial No. 363,463.,

To wZZwiom/t may concern:

Be it known that I, CHARLES E. M ILLER, a citizen of the United States, and resident of Chicago, in thecounty of Cook and State of Illinois, have invented certain new and useful Improvements in Locomotive Arches, of which the following-isavspecilication.

My inventief: relates to improvements in combustion chambers for 4steam boilers and has special reference to an improved refractory arch or baffle for use in a locomotive: tire box. j

It is usual to provide inclined water tubes in a locomotive fire box which extend from the lower part of the flue sheet rearwardly and upwardly to the rear fire box sheet, for increasing the production of steam and causing a forced circulation of. the water in the boiler. I

It is common practice to arrange refractory slabs or fire bricks on these lnclined tubes to provide a refractory arch or baile between theg'rate and the iiue sheet to cause the burning fire box gases to rise into coni tact with the crown sheet and the side sheets of the fire box on their way to the Hues which lead forward through the boiler to the smoke box atthe forward end.

The early arches of this character were made of large flat slabs laid directly on the inclined tubes and 'reaching substantially from side sheet to side sheet. These large slabs were not satisfactory in thatthey were difiicult to getl into the fire box and to place in position and were subject to quick deterioration and destruction, soon breaking to pieces and falling down into the lire. Ibe next step was to build the arch of small bricks or pieces adapted to be put into the tire box 40 through the vordinary ii're door and adapted tospan frein tube to tube and having inclined ends for contact with the tubes which lent a degree of adjustment between the spacing/'of adjacent tubes and the lengths of the bricks.

It was found that a solid or tight built arch with the bricks laid. close together did not give the best results and that it was desirable to space the bricks apart longitudi- 5@ nally of the tubes to permit some of the gases to pass directly through the arch. rIhe advantage of this is that 'these streams of hoef gasesl passing through the arch cause a thorough mixing of the gases flowing around and over the arch and serve to malutam a higher temperature in the lire `box between the arch and the flue sheet and prevent the cooling of the main body of gases to a point below ignition.

It. has been proposed to space the bricks on the tubes and retain them in spaced relation by means yof `small or short U-shaped spacing blocks adapted to hang on the tube between the a'rch bricks. These small spacer bricks have not proven satisfactory. They are too fragile and easily displaced frequently turning around on the tubes and falling 'off and as it is necessary to clear the holes through the .arch from time to time of slag and other obstructions, these small fragile 1 spacing blocks are subject to bev cracked,

-broken and displaced and the arch thus destrOyed. When these spacer blocks are displaced the arch. bricks become displaced by sliding down the inclined tubes and frequently they fall off. of the tubes 'thus' dis* placing the arch.

By means of' my invention I eliminate all of the detrimental features above mentioned. I rovide a locomotive fire box arch which is substantially permanent, once itis installed; which has ian even distribution of perforations over its ent-ire area, the several bricks having integral spacing projections on the-ir tube supported ends, which projections not only tween the projections and whenv the bricks are-placed in position these cut away portions forin the perforations or slots extending through the arch from the under side to the top or back of the arch.

I have embodied several 'other features in the brick and arch of my invention. which tend not only to reduce manufacturing costs, but also to add endurance or life to the arch as well as-to add greatly to the eiliciency of the arch in its function of assisting in caus ing and maintaining perfect combustion and protecting the inclined tubes from thescouring or cutting effect of the blastsr of high temperature burning gases and the solid fuel particles carried thereby and impinging directly thereon.

I makethe individual bricks of -which I build my improved arch of a peculiar arched form which simulates to some extent the arch ofthe bridge, the ends being thin and the middle portion being considerably thickened and arched up. This form not only 85 holdthe bricks in position but the lateral edges of the bricks are cut away be makes a brick and an arch which is exceedingly durable but in a sense provides troughs for the rising gases between the ,inclined tubes which troughs are maintained at a maximum temperature and serve to ignite the gases as they rise into contact therewith. This formation also serves, to some extent, to protect the tubes from the hottest and most destructive gases.

The peculiar shape which I use provides a sharply defined longitudinal center pla-ne of the brick of maximum thickness, thus providing the greatest thickness at the point of greatest abrasion and deterioration as well as at the point of greatest strain, and consequently the brick is long lived.

The ends of my improved brick are cut out at their lower edges to provide grooves curved to substantially t the tubes upon which the bricks are supported and the upper edges at the ends of the brick extend over the tops of the tubes, substantially to the center plane thereof. This construction permits of a degree, of variation in the spacing of the tubes without necessitating different lengths of bricks and also covers and protects the upper sides or tops of the tubes againstl the abrasive and cutting action of the gases flowing over the top and down the back of the arch.

My invention will be more readily understood by reference to the accompanying drawings illustrating my invention and'in which:

Fig. 1 is a diagrammatic horizontal section of a locomotive fire box equipped with a refractory arch constructed of my novel arch brick land embodying my invention;

Fig. 2 is a top plan view of one of the arch bricks; and,

Fig. 3 is an end elevation of one of the arch bricks. In said drawing, l represents the lire box of a locomotive boiler, having a iiue sheet 2 at its forward end a rear sheet 3 at its opposite end and side sheets 4.

The fire box is provided with a number of substantially parallel water circulation tubes 5 which extend from the lower part of the iue sheet to the upper part of the sheet and assist in the rapid production of steam and the rapid circulation of the water in the boiler.

Upon the forward ends of the tubes I construct aA refractory arch G made up of a plurality of transverse and longitudinal f rows of refractory arch bricks of two forms.

7 and 8. The bricks 7 span from tube to tube and the bricks 8 fill in between thelside tubes and the side sheets of the fire box.

The center bricks 7 are all substantially identical in that they are all of the same pattern and where the tubes 5 are parallel. as shown, they are of uniform size.

As the tire box widens toward the flue sheet the side bricks may vary somewhat in length in the several transverse rows, but evensothey have several of the characteristics of the bricks 7.

lThe arch bricks 7 rest at their ends on the tubes 5 and are provided at the lower edges of their ends with quarter circle grooves 9 substantially fitting the outer surface of the tubes and arranged to extend' substantially to the top of the 'tubes and down to about the middle of the tubes, so that the brick is not only supported by the tubes upon which it rests, but is also held against movementv transversely of the fire box.

The brick thus formed is practically provided with end shoulders l() which engage the sides of the tube 5 and hold the brick against movement transversely of the fire box and with supporting flanges l1 at their ends which rest upon the tubes and cover them. The spacing of the two grooves 9 is such in reference to the spacing of the tubes that slight lateral play or clearance is provided between the tubes and the shoulders 10 to allow for expansion of the bricks and to allow for some variation of the spacing of they tubes.

The brick is arched or curved upwardly from the supporting ends forming a truc arched brick and in which form the brick canbe made considerably lighter than the old form of flat wedge brick and yet maintain or even increase its supporting strength.

I preferably form the under surface l2 of the brick on a curve struck from a single center -13 and vof a radius of a length lto raise the center pointl 14 of the brick substantially to the level of the top surface of thetubes upon which the brick rests. Instead of forming the upper surface l5 of the brick l on a. single curve or one parallel with the under surface, I preferably strike it from two centers 16, each on the opposite side of the vertical center line from the part of the brick formed thereby and of less length than the radius of the under surface. By this means I form an arched brick which is considerably thicker at its center than at its ends and which increases to a sharply defined maximum thickness at the transverse center plane of the brick.

It is well known that the scouringl action of the risingr fire box gases and the mpingement on the under side of the arch of the. solid particles of fuel carried upward by the excessively strong forced draught used in locomotive practice tend to wear away the under side of the arch bricks.

An arched brick formed as above described, has a longer life than one of uniform thickness from end to end and made fiat for being arched and consequently selfbracing, it will usually remain uncracked ilu Withthe old form of wedgingbricks.- Also portion has been reduced to a thickness even that bricks of the type shown do not produce a spreading Vor wedging action to lspread Vthe tubes apart, the tubes merely 'carrying the-weight'of thevbricks 'and not holding them 11p-'by a vwedging action.

Y' As explained hereinbefore, it is advisable. 13o-provide the archwith openings extendingy through the arch from the lower side 'to the upper side 'orback of the arch and for this purpose I providethe bricks with .spacing projections 18 Aat their ends extending longitudinally of -the tubes. Between e the projections 18 the sides of the brickare `cut away to provide shallow recesses 19 extending from the under side to the back of the'brick; When the bricks lare assem-A bled onthe tubes 5 the recesses 19 in adjacent bricks between or resting on the same tubes form openings'20 inthe arch through which the gasesof combustion can flow di'- arch..

I These stream-stof burningfgases which thus flow through the alte/haat. many points lare at substantially.v temperature, they areusually overcharged with oxygen A and-by means of "the strong forced draught used inlocomotivefpractice these streams are projected withf'considerable forceinto the bod oi ycombustion `gases flowing down the bac of the arch toward the flue sheet. This plurality of thin narrow streams of combustion gases rising through the openings 20 cause the 4thorough intermingling an 'mixing of the body of-gases, probably adding oxygen, and assisting in maintaining the temperature of the main body of gases' up to the combustion temperature and consequently resulting in the thorough andcom- I' plete combustion of the fuel.

The side bricks 8 are supported at their inner ends on the outer tubes and 'are usually leanedl against the side sheets in an upwardly inclined position as indicated, but

' however they are supported they are likewise provided with the integral spacing projections 18 and formed'with the recesses or spaces 19 in their lateral edges,

ing the arch lwith the openings 20 between the iouter tubes and the side sheets as 'well' v as in the parts of the arch between the tubes.

It' is desirable that Aconsiderably enlarged Yopenings 21 be provided between the lower or forward end of Athe arch and the iue sheet to permit'relatively large streams of the burning gases to flow -around the lower end of the -arch into the lowermost of the boiler tubes 22. For supportingthe arch .thus spaced from the ue sheet I provide filler or spacer blocks 23 adapted to be supported on the tubes 5 and held tightly between the arch and the iiue sheet 2. As

the whole downward thrustof the arch is .sustained by these blocks they'are securely heldin position and are not subject-to destruction and displacement as the relatively .small Uv-shaped spacer blocks ordinarily used 1. refractory arch brick for sup ort upon water tubes in -a fire box, the en s of rectly from the ,fuelbed 'to the back of the "i thebrick having quarter circle grooves for receiving the supporting tubes,andthe brick arched up'between Vits ends, the middle partof the brick being thicker than -its ends, substantially as described.

2. A refractory arch brick adapted to be supported upon water tubes in a rebox,

'of thelower side whereby the brick is thicker. vatits middle portion "and tapers towards both ends, substantially as described.

the under surface of the brick being formed formed 'upon two d the brick and of shorter radius t an that 3. Avrefractory arch brick of the kind de scribed having tube receiving grooves at its -no i ends and being arched up between its ends, the brick being thickest at its middle ortion and curved downwardly and tapere toward each end, substantiallA asfdescribed.

Signed at Chicago, Illinmaithis 2nd day.

of March, 1920.

" 4 CHARLES MILLER.

Witness i thus provid- BUTLER. l 

